<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body style="text-align: center">
<div style="width:auto">
<div style="float: left;width:70%;text-align: right">
<canvas id="paintP" ></canvas>
</div>
<div style="float: right;width:30%;text-align: left">
    <input id="btnref" type="button" value="重新加载"/>
</div>
</div>
</body>
</html>